Plug Assembly with Sloped Walls

ABSTRACT

A glass assembly including: a plug with a top surface and a bottom surface; a sealing bearing ring at least partially made of a non-elastomeric material; wherein: the sealing bearing ring arranged on the top surface or the bottom surface of the plug. Also, a plug assembly including: the glass assembly, arranged in a housing the glass assembly including a top surface and a bottom surface; a sealing bearing ring at least partially made of a non-elastomeric material the sealing bearing ring arranged on the top surface or the bottom surface of the plug; a seat arranged to support the plug; a breaker object configured to break the plug; and wherein the sealing bearing ring provides a seal between the glass assembly and the housing.

The present application is a Continuation in Part of, and claimspriority to, U.S. application Ser. No. 17/480,805 filed Sep. 21, 2021;hereby incorporated by reference.

FIELD OF INVENTION

The present invention relates to a plug assembly for the temporaryblocking of fluid flow through a downhole tubular. More specifically itrelates to sealing capabilities of a bearing ring and other componentsof the glass assembly in said plug assembly.

BACKGROUND

During the drilling, testing, completion, fracking, production, andabandonment stages of hydrocarbon wells there are many uses for plugsassemblies that create a fluid barrier in the well. Some of these usesare not permanent such as plug and abandonment, but rather temporary,where it is desired to re-establish fluid flow at a later stage. Someexamples of such temporary uses of plugs are for flotation, well testingduring completion, packer setting and fluid loss devices. Temporaryplugs may thus be installed in any kind of piping installed downhole,for example casing, liner, or other tubing. The only difference betweenthese is the inner diameter of the pipe.

When flow through the well is to be established, the plug is broken.This preferably done without spearing, milling, or other mechanicalintervention from the surface. Ways to achieve the desired breaking isthrough the use of pressure, pressure pulses, or explosives. When theplug is removed it allows for a nonrestricted fluid flow past the openedplug assembly, and for many applications after opening of the plugassembly this is required in order to pass various tools past the plugassembly. Plugs can be made of various materials, such as metal, stone,or composites, or more frangible materials such as glass or ceramics.Frangible materials are often preferred as they have the advantage ofbeing relatively insensitive to pressure, temperature and chemicalcorrosion, yet by their frangible nature they are relatively easy todestroy when used as the fluid blocking part of plug assemblies.Particularly glass, e.g., hardened glass, can be made to break into verysmall pieces that will not pose a problem in most wells. Frangiblematerials are therefore well suited for opening the plug assembly byconstructing the plug assembly with a breaker of small amounts ofexplosives that will crush or shatter a glass disc, and open the plugassembly, but not damage the production tubing or casing the plugassembly is installed in. The breaker will then make contact with theplug on a relatively small area. Frangible materials will typicallyshatter, and this property of breaking under a large point pressure loadis taken advantage of by employing a breaker object with a relativelysmall impact area, such as a thin edge like a knife blade, a point suchas a pin, or even a small ball.

A problem with many frangible materials is that they can prematurelybreak where they contact a hard surface such as a metal surface. Thiscan happen when the plug is being installed or even when changes inpressure in the well causes minute movements of the glass assembly. Oneway to overcome this issue is to put a bearing ring of a soft material(e.g., plastics such as polyether ether ketone; PEEK) between thefrangible plug and any hard surface (e.g., steel) it abuts. This allowsthe force on the plug to be transferred to the bearing ring instead. Thebearing ring will then compress and prevent the plug from coming incontact with a hard surface.

The plug should be installed in such a way that it is well secured andwill not break easily from fluctuating well pressures (i.e. from directpressure rather than from a breaker). The plug should also be secured insuch a way that it forms a fluid tight seal as the specifications of thespecific application require until it is removed. Leakage of fluidbetween the plug tubular and the surrounding area, such as the annulus,should be prevented as far as possible.

Loose parts in the wellbore can cause a lot of damage to equipment andeven obstruct the well bore. Thus, the plug should preferably break intofragments small enough to not be a potential problem in the well. Thevarious other parts of the plug assembly should preferably be preventedfrom entering the wellbore when breaking the plug, so they or piecesthereof will not be a potential problem in the well. These other partsshould also preferably be prevented from moving once the plug assemblyis opened. There should not be a possibility of a partial opening of theplug, i.e. the system should preferably only allow for the plug to befully intact or fully broken, not partially broken. If partially broken,it would not be possible to open fully with pressure from above since apartially open plug assembly could not be pressurized, so differentmeans to open it fully would have to be used.

The inner diameter of the tubing the plug assembly is installed inshould preferably be fully restored upon opening of the plug assembly,i.e. the plug assembly should not have a smaller inner diameter than theinner diameter below and above the plug assembly. This allows for anonrestricted fluid flow past the opened plug assembly, as well asunrestricted passing of tools up to the inner diameter of the pipe theplug sits in.

Advantages of the Present Invention

It is an object of the present invention to provide a plug assemblycomprising a plug that can hold pressure while being used for itspurpose, and then be safely and completely opened after it has servedits purpose. Once open, the plug assembly parts should stay in place,and said parts or pieces thereof should not enter the wellbore.

It is an object of the present invention to provide a plug assemblycomprising a plug that has an improved sealing of said plug before it isopened. Another object of the present invention is to provide a plugthat is less likely to be prematurely broken during assembly, insertioninto the well, or by movement of the plug tubular in the pipe (e.g. frommovement or pressure changes in the pipe or formation). This is achievedby the geometries of the plug and/or stabilizer and/or glass assembly.

By the plug not having sharp corners, but rather rounded edges, it isless likely for said rounded edges to be chipped off during assembly, orwhen the plug experience relative movement against the surroundingcomponents, such as when the plug is inserted into the well, or the plughousing shifts with the formation, or when the pressure applied from uphole or downhole or the formation changes.

Usually there is no bearing ring or stabilizer between a plug surfaceparallel with the plug housing and said housing or sleeve or whatevercomponent the plug is to seal against. By adding the stabilizer, ithelps stabilizing and centralizing the plug in place. If made of asofter material, similar to the materials the bearing rings are made of,it also helps cushion the side of the plug against any sideways impacts,and gives it a little extra play for movement. Rig operators are oftenconcerned that u plugs are exposed to impacts and vibrations both duringtransport and operation, and therefore it is usually required that theplug assembly must be able to withstand shock and vibrations. Adding astabilizer helps fill this requirement.

Not being bound to a specific theory, possible reasons for the improvedsealing of the seals when on a surface not parallel to the plug housingbut rather sloped is that the seals will receive less force than when ona surface parallel to the plug housing, such as at a parallel side ofthe plug. Such nonparallel surfaces may be better supported by the plugand housing. Thus, the seals may experience less force trying to pushthem out of the way. The seals would also have to move further, so itwould take more force, to move them when on the sloped walls than whenon a parallel, straight up and down wall. The pressure on the sealsresults in less of a risk of extrusion of said seals (e.g. O-rings), asthe gap will be closed by the forces applied by the pressure. This maythen lead to the seals being able to take higher pressure and leak less.This effect would be especially advantageous when the seals are alsopressed up against the stabilizer, in which case this holds them well inplace. Thus, this allows for better force distribution and reduceddeformation of both seals and bearing rings under different pressuresand temperatures to increase protection of the plug and form a betterseal. The combination of the seals and the stabilizer provide animproved effect for both as they can help hold each other in place.

When the various parts for the glass assembly are made, they will ofcourse be made to specifications, but there will usually be somevariation in their manufacturing tolerances. This can cause assembly tobe difficult, and the final seal to be not optimal. For example, if thecomponents of the glass assembly are made slightly larger thanspecified, the seal will be very tight and the assembly hard to get intoplace. Likewise, if too small, the seal achieved may not have quiteenough pressure on it from the components and may leak. The heightadjustor addresses these problems. By loosening it, insertion of theglass assembly into its place in the housing is easy. When the glassassembly is put in place, the height adjustor can be adjusted so itapplies just the right amount of pressure on the glass assembly, not toomuch pressure which could ultimately crack the plug or damage othercomponents, and not too little pressure so the seal would be too looseand could leak, but just right to form a proper seal

Short Summary of the Invention

In some aspects, the techniques described herein relate to a glassassembly including: a plug with a top surface and a bottom surface; asealing bearing ring at least partially made of a non-elastomericmaterial; wherein: the sealing bearing ring arranged on the top surfaceor the bottom surface of the plug.

In some aspects, the techniques described herein relate to a glassassembly, further including a non-sealing bearing ring, wherein thebearing ring is on the opposite surface of the plug from the sealingbearing ring.

In some aspects, the techniques described herein relate to a glassassembly, further including a stabilizer and wherein: the plug furtherincludes a middle edge surface which contains the widest portion of theplug; and the stabilizer is arranged around at least a portion of themiddle edge surface.

In some aspects, the techniques described herein relate to a glassassembly, further including a stabilizer and wherein: the plug furtherincludes a middle edge surface which contains the widest portion of theplug; and the stabilizer is around the middle edge surface.

In some aspects, the techniques described herein relate to a glassassembly, wherein the sealing bearing ring is entirely made of anon-elastomeric material.

In some aspects, the techniques described herein relate to a glassassembly, wherein the stabilizer is made of a non-elastomeric material.

In some aspects, the techniques described herein relate to a glassassembly, wherein the stabilizer is not fluid tight.

In some aspects, the techniques described herein relate to a glassassembly, wherein the sealing bearing ring includes a thermoplasticmaterial.

In some aspects, the techniques described herein relate to a plugassembly including: a glass assembly, arranged in a housing the glassassembly including a top surface and a bottom surface; a sealing bearingring at least partially made of a non-elastomeric material the sealingbearing ring arranged on the top surface or the bottom surface of theplug; a seat arranged to support the plug; a breaker object configuredto break the plug; and wherein the sealing bearing ring provides a sealbetween the glass assembly and the housing.

In some aspects, the techniques described herein relate to a plugassembly wherein the glass assembly further includes a non-sealingbearing ring, wherein the bearing ring is on the opposite surface of theplug from the sealing bearing ring.

In some aspects, the techniques described herein relate to a plugassembly, wherein the sealing bearing ring is made entirely of anon-elastomeric material.

In some aspects, the techniques described herein relate to a plugassembly, wherein the glass assembly has an uphole and downhole side,wherein no bearing ring or sealing bearing ring on the uphole side ofthe in the glass assembly, and the sealing bearing ring is arranged onthe downhole side of the glass assembly.

In some aspects, the techniques described herein relate to a plugassembly, wherein the glass assembly further includes a stabilizer andwherein: the plug further includes a middle edge surface which containsthe widest portion of the plug; and the stabilizer is arranged around atleast a portion of the middle edge surface.

In some aspects, the techniques described herein relate to a plugassembly, wherein the glass assembly further includes a stabilizer andwherein: the plug further includes a middle edge surface which containsthe widest portion of the plug; and the stabilizer is arranged around atleast a portion of the middle edge surface.

In some aspects, the techniques described herein relate to a plugassembly, wherein the stabilizer is not fluid tight.

In some aspects, the techniques described herein relate to a plugassembly, wherein the stabilizer is not fluid tight.

In some aspects, the techniques described herein relate to a plugassembly, wherein the seat is arranged to move in an axial directiontoward the breaker object when a threshold absolute pressure orthreshold differential pressure is reached.

In some aspects, the techniques described herein relate to a plugassembly, further including a shear ring, the shear ring including ashear ring lip wherein the seat is supported by the shear ring lip, theshear ring lip arranged to shear and allow the seat to move when athreshold absolute pressure or threshold differential pressure isreached.

In some aspects, the techniques described herein relate to a plugassembly, further including a breaker holder, wherein the breaker holderis configured to hold the breaker object fixed in place relative to theplug.

In some aspects, the techniques described herein relate to a plugassembly, further including a sealing area, wherein the sealing area isthe region of the housing and seat in contact with the sealing bearingring and wherein, the sealing area is non-parallel with the axial axisof the plug assembly.

In some aspects, the techniques described herein relate to a plugassembly, wherein the sealing bearing ring has a through hole thatprevents the sealing bearing ring from sealing at a parallel portion ofthe housing.

In some aspects, the techniques described herein relate to a plugassembly, wherein the glass assembly has an uphole and downhole side,wherein there is no bearing ring or sealing bearing ring on the upholeside and the sealing bearing ring is arranged on the downhole side ofthe glass assembly.

BRIEF DESCRIPTION OF THE FIGURES

The above and further features of the invention are a set forth withparticularity in the appended claims and advantages thereof will becomeclearer from consideration of the following detailed description.Embodiments of the present invention will now be described, by way ofexample only, with reference to the following diagrams wherein:

FIG. 1A discloses a side view of a longitudinal cross section of a firstexample of a plug tubular

FIG. 1B discloses a close up of the glass assembly of FIG. 1A

FIG. 1C discloses a perspective cross-section view of a second exampleof a plug tubular

FIG. 1D discloses a side view of a longitudinal cross section of a thirdexample of a plug tubular

FIG. 2A shows a side cross-section of an example of a glass assemblywithout curved surfaces

FIG. 2B shows an exploded view of an example of a glass assembly withoutcurved surfaces

FIG. 2C discloses a perspective cross-section of an example of a glassassembly

FIG. 2D discloses an exploded view of the example of FIG. 2C

FIG. 2E discloses a perspective cross-section of an example of a glassassembly with multiple plugs

FIG. 3A discloses a side view of a longitudinal cross-section of theoperation of a plug tubular in the first position

FIG. 3B discloses a side view of a longitudinal cross-section of theoperation of a plug tubular in the transition between the first andsecond positions

FIG. 3C discloses a side view of a longitudinal cross-section of theoperation of a plug tubular in the second position

FIG. 3D discloses a side view of a longitudinal cross-section of theoperation of a plug tubular in the third position

FIG. 4 discloses a side view of a longitudinal cross section of anexample of a glass assembly with a height adjuster

FIGS. 5A-5C shows a cross-sectional side view of examples of plugsurface geometries without curved surfaces

FIGS. 5D and 5E disclose a cross-sectional side view of examples of plugsurface geometries with curved surfaces

FIG. 6A discloses a side view of a longitudinal cross section of anexample of a plug tubular with a plug assembly in the first position

FIG. 6B discloses a closeup of the plug tubular example of FIG. 6A

FIGS. 6C-6F discloses the plug tubular example of FIG. 6A as the plugassembly moves from the first position to the second position

FIG. 7 discloses another example of a plug assembly

FIGS. 8A and 8B disclose an example of a height adjuster as the plugassembly in the first and second positions

FIG. 9 discloses an 3D exploded view of an example of a plug assembly

REFERENCE NUMBERS AND CORRESPONDING ELEMENTS

-   10 Plug 10-   11 Sealing Element 11-   12 Stabilizer 12-   13 Sealing Area 13-   14 Bearing Ring 14-   15 Glass Assembly 15-   16 Sealing Bearing Ring 16-   17 Sealing Bearing Ring Edge Groove 17-   60 Plug Surface 60-   61 Top Surface 61-   62 Bottom Surface 62-   63 Top Edge Surface 63-   64 Middle Edge Surface 64-   65 Bottom Edge Surface 65-   66 Edge Surface-   20 Seat 20-   21 Seat Surface 21-   22 Breaker Pocket 22-   23 Seat Lip 23-   24 Seat Pocket 24-   30 Breaker Object 30-   31 Breaker Holder 31-   32 Breaker Assembly 32-   40 Height Adjuster 40-   41 Adjustable Seat 41-   42 Mechanical Adjuster 42-   50 Shear Ring 50-   51 Shear Ring Lip 51-   52 Shear Ring Body 52-   100 Plug Tubular 100-   110 Upper Tubular 110-   120 Lower Tubular 120-   130 Tubular Body 130-   140 Housing 140-   200 Plug Assembly 200

DETAILED DESCRIPTION OF THE INVENTION

Reference will now be made in detail to the present embodiments of theinvention, examples of which are illustrated in the accompanyingfigures. Alternative embodiments will also be presented. The figures areintended to be read in conjunction with both the summary, the detaileddescription, and any preferred and/or particular embodiments,specifically discussed or otherwise disclosed. This invention may,however, be embodied in many different forms and should not be construedas limited to the embodiments set forth herein. These embodiments areprovided by way of illustration only. Several further embodiments, orcombinations of the presented embodiments, will be within the scope ofone skilled in the art.

As described, there are various ways to open plugs. In the examplesgiven below, the plugs are opened applying pressure, which brings abreaker object 30 into contact with the plug 10, causing it to break.The breaker object 30 does not have to be operated in this manner.Instead applied pressure or a different kind of signal such as thatprovided by a control line could cause the breaker object 30 to bebrought into contact with the plug 10, or it could cause the breakerobject 30 to explode, and this explosion could break the plug 10. Insome cases the seat 20 will not necessarily move in an axial direction,or move at all. Alternatively, the plug 10 may be designed to be brokenby milling it open. The plug 10 could then be arranged in a glassassembly 15, and said glass assembly 15 could be directly secured in thehousing 140.

Plugs that can be opened using pressure, operate upon the principle of aplug 10 arranged in a housing 140 of a plug tubular 100. The plug 10 ispart of a glass assembly 15 which prevents fluid connection between theupper tubular 110 on the upstream side of the plug and the lower tubular120 on the downstream side of the plug. A glass assembly 15 comprisesthe plug 10 and is arranged on a seat 20 for support. Pressure isapplied to one side of the plug (normally from the upstream side). At apredetermined absolute pressure, or a predetermined differentialpressure, the seat 20 moves in an axial manner until the plug 10 makescontact with a breaker object 30. Upon contact, the plug willdisintegrate, and flow through the tubular 100 is restored. The sealingarea 13 is the area or areas where it is fluid tight between the plug 10and the tubular body 130 and/or the plug 10 and the seat 20. Please notethat although the examples below refer to a plug 10 opened by applyingpressure from above, e.g. a so-called pump open type plug, it is alsopossible to open the plug 10 with by applying pressure from below (orreducing pressure above), e.g. a so-called surge open type plug. Alsonote that the plug assembly 200 can be used in a casing, a liner, atubing, or any other metal pipes used downhole, with any outer and innerdiameters.

One important feature for this invention is the curved outermost edge ofthe plug 10 and details of the sloped or perpendicular sealing area 13.

FIGS. 1A-1C disclose examples of a glass assembly 15 with a plug 10 in aplug tubular 100. The plug 10 prevents fluid connection between thefluid inside the upper tubular 110 on the upstream side of the plug andthe fluid on the downstream side of the plug inside the lower tubular120. The glass assembly 15 is arranged on a seat 20. At a predeterminedabsolute pressure, or differential pressure, the seat 20 moves in anaxial manner until the plug 10 contacts a breaker object 30. Uponcontact with the breaker object 30 the plug will break and flow throughthe tubular 100 is restored.

The plug tubular 100 comprises a plug assembly 200 arranged in a housing140 in a tubular body 130. The tubular body 130 comprises an uppertubular 110 on the upstream side of the plug 10 and a lower tubular 120on the downstream side of the plug 10. The plug assembly 200 comprises aglass assembly 15, a seat 20, a breaker assembly 32, and a shear ring50.

The glass assembly 15 comprises a plug 10, a sealing element 11, astabilizer 12 and a bearing ring 14. The sealing element 11 preventsfluid from traveling around the plug 10. In the example shown, this isfound between the plug 10 and the housing 140 on one side and the plug10 and the seat 20 on the other side. A bearing ring 14 is arrangedbetween the plug 10 and the housing 140 one side and the plug 10 and theseat 20 on the other side. A common example of a sealing element 11 isan O-ring. Note that while glass assembly 15 is called a “glassassembly” it refers to the plug 10 (regardless of material, includingnon-glass materials).

The sealing area 13 is the area on the housing 140 and seat 20 that isin contact with the sealing element 11. It is this area which accountsfor the plug 10 being fluid tight. The sealing element 11 could bearranged on the outside of the plug 10, in a groove in the plug 10, or agroove in the housing 140 and/or seat 20. As will be disclosed below, itis also possible for other elements to be fluid tight as well. Thoseelements will further contribute to the sealing area 13, but the oftenthe main seal is formed by the sealing element 11. The sealing area 13does not include the areas in which a fluid tight seal is not provided.

The stabilizer 12 helps to hold the plug 10 in place during operation.Depending upon the exact configuration, it may be possible for the plug10 to twist in the housing 140 without it. Also, similar to the bearingring 14 (discussed shortly) it can keep the edge of the plug 10 frommaking contact with any hard metal surface. The stabilizer 12 shown inall of the figures is curved to match the curved shape of the middlesurface of the plug 10. The stabilizer 12 could also be called a middlebearing ring due to its position in between the two “outer” bearingrings 14.

While it is possible for the bearing rings 14 and/or stabilizer 12 toseal somewhat against fluid, and thus be included in the sealing area13, it is preferable that the stabilizer 12 is not fluid tight. Forinstallation, by cutting slits or separations in the stabilizer 12, itwill make it easier (or perhaps even possible depending on the exactgeometries) to install. If the stabilizer 12 is such a cut ring, the twoends of the cut can be made to overlap to make the diameter of thestabilizer 12 smaller so that it can be easily inserted. Depending uponthe material and/or geometries, this may be necessary. Slits will renderthe stabilizer 12 non-fluid tight and completely ineffective as asealing component. Additionally, another reason for not requiring thatit be fluid tight is that a wider choice of materials is then available.

The main purpose of the bearing ring 14 is to help reduce thepossibility of contact between the plug 10 and hard metal surfaces (e.g.the housing 140 and the seat 20). At higher pressures, a contact betweena hard metal surface and the plug 10 could result in a prematurebreaking. Common materials for bearing rings 14 are soft enough toprovide cushioning between the plug 10 and adjacent hard components,such as the seat 20 or housing 140, thus preventing premature breakingof the plug.

An example of such materials are soft metals, rubber or plastics,preferably PEEK. Materials for a stabilizer 12 also include the samesoft materials as are used for bearing rings 14, but hard materials suchas those used for the other plug assembly components may be used, suchas steel or glass.

If needed, the sealing element 11 can be held in place by a stabilizer12 and/or a bearing ring 14. A stabilizer 12 prevents the sealingelement 11 from being pressed toward the outside of the plug 10, and abearing ring 14 can help hold the sealing element 11 from being pressedtoward the inside of the plug when under operation.

A breaker assembly 32 is an element that contains and supports thebreaker object 30. A breaker object 30 is arranged to break the plug 10when they make contact. In the example shown, the breaker object 30 isheld in a breaker holder 31. It is also possible for the breaker object30 to be directly affixed to the housing 140.

The glass assembly 15 is supported by the seat 20. The plug 10 will bedirectly or indirectly supported by the topmost portion of the seat 20,the seat surface 21. When the seat 20 moves in an axial direction, theplug 10 will move with it. In the example shown, the seat 20 has abreaker pocket 22 that is arranged such that the breaker object 30 passthrough the seat 20. The seat 20 has a seat lip 23. This is a protrusionthat extends past the shear ring lip 51 of the shear ring 50. Becausethe seat 20 extends at least a portion past the edge of the shear ringlip 51, the shear ring lip 51 is held in place when plug assembly 200has completed its operation. Beneath the seat 20 is the seat pocket 24.The seat pocket 24 is a space that can receive the seat 20 when it movesin an axial direction under operation.

A shear ring 50 is arranged such that it supports the seat 20 on itsshear ring lip 51. When the proper threshold pressure (absolute ordifferential) is reached, the shear ring will break into two differentpieces. One portion will remain stationary, and the shear ring lip 51will travel axially. Note that instead of a shear ring, shear pins, orother such elements could be used. Note that the shear ring 50 can havedifferent shapes. That of FIGS. 1A and 1B have the shear ring lip 51 adistance from the edge of the shear ring 50 (this is sometimes referredto as a “T” shape), while that of FIG. 1C has the shear ring lip 51 onthe edge of the shear ring 50 (sometimes referred to as an “L” shape).The purpose of the shear ring 50 is to shear into two pieces, the exactarrangement can be as required for a given application. By changing thethickness of the shear ring lip 51 or making it discontinuous around theedge of the shear ring 50, it can be easily adjusted to shear atdifferent applied pressures. The shear ring lip 51 can then preferablybe changed in thickness in the downward direction in the figures, asthis protrudes into the hollow space of the receiving pocket 24 and noother components will have to be changed. It is also possible to makethe shear ring 50 from different materials with different mechanicalproperties, and hence change the shear value.

Depending upon operating conditions and material composition concerns,it may be possible for the glass assembly 15 to include a plug 10 and asingle sealing element 11, or a plug 10 and a stabilizer 12.

FIG. 1D discloses another example of a glass assembly 15 with roundededges. The plug 10 in this example is different from the previous one.Rather than the rounded portion being in between two chamfered angledportions, the rounded portion is between a flat horizontal portion onthe figure and an angled bottom portion. The glass assembly 15 comprisesa plug 10, a sealing element 11 between the plug 10 and housing 140 andanother sealing element 11 between the plug 10 and seat surface 21, abearing ring 14 between the plug 10 and the housing 140 and a bearingring 14 between the plug 10 and the seat surface 21, and a stabilizer 12between the plug 10 and the housing 140 and/or seat surface 21.

It is possible that the stabilizer 12 is made up of more than oneseparate piece. For example, this could be due to the physicaldimensions of the system or the shape of the plug 10 or housing 140 orseat 20. It could also make installation simpler. As shown in theprevious figures, the bearing ring 14 and the stabilizer 12 help to holdeach of the sealing elements 11 in place.

Also shown is the arrangement where the seat lip 23 is held in place bythe shear ring lip 51 to prevent the shear ring lip 51 from entering thewellbore.

The preferred angle of the chamfers is between 1 and 45 degrees,preferably 25 to 45 degrees, measured from the centerline. 90 degrees(perpendicular to the centerline) is also a good alternative. The radiusof curvature of the rounded outer edge is preferably between 1 mm and 10mm. The angle on the overside and underside of the plug does not need tobe the same.

While the tubular body 130 in the figures is shown as comprising anupper tubular 110 and a lower tubular 120, it could also be made of asingle continuous piece. In FIG. 1D, the rounded portion of the plug isbetween the top surface and the edge surface, as opposed to that of themiddle. This is where the widest part of the plug 10 meets a surfacewith a different angle. Further details of the surface geometry will bediscussed in FIGS. 5A-5E.

FIGS. 2A and 2B shows glass assemblies without curved surfaces. The topand bottom edge surface of the plug 10 is chamfered. On these chamfersis arranged a bearing ring 14. The sealing element 11 is arranged at themiddle portion of the plug 10, which is straight. There is no stabilizer12 or rounded middle edge surface as given in FIGS. 2C and 2D. In FIG.2D, the stabilizer 12 is shown with a split in order to facilitateeasier installation.

FIGS. 2C and 2D disclose an example of a glass assembly 15 with a curvededge surface. The plug 10 has a chamfer/bevel on the top and bottom edgesurfaces with a rounded portion connecting them. On these top and bottomedges is arranged a bearing ring 14. As stabilizer 12 is arranged incontact with the rounded portion of the plug 10. Sealing elements 11 arearranged between each bearing ring 14 and stabilizer 12.

The plugs 10 shown in FIG. 2A and FIG. 2B plug 10 has some combinationof vertical, chamfered, or beveled edges. In particular, the widestportion of the plug 10 has a vertical edge. However, where two straightedges meet (e.g. a corner or a chamfer), that point is vulnerable tostress. Especially the area between the widest part of the plug and thefirst surface with a different planar angle has a higher chance ofbreaking. Please note that the plugs 10 of the examples of FIGS. 2A and2B are the same, but the glass assemblies 15 differ in that while thereis only one sealing element 11 in FIG. 2A, there are two sealingelements 11 shown in FIG. 2B. If the righthand sealing element 11 ofFIG. 2B were removed, this figure would depict an exploded view of FIG.2A.

Under higher pressures, these areas can become susceptible to prematurebreakage. However, the plug 10 in FIG. 2C and FIG. 2D as shown has achamfered edge on the top and bottom and a rounded edge between them.This gives the outermost edge of the plug 10 a curved profile. Thiscurved profile allows the plug 10 to be more robust against unwantedbreakage than a sharp corner would be.

FIG. 2E discloses an example of a glass assembly 15 made of multiplelayers. This can either be multiple layers of material in the same plug10 (as shown in the example) or multiple discrete plugs 10 in the glassassembly 15. The example shown has a bearing ring 14 at the top andbottom portion of the plug 10, and a stabilizer 12 which covers themiddle edge of the plug 10. A sealing element 11 is arranged between thebearing ring 14 and the stabilizer 12 on both sides of the plug 10.While the stabilizer 12 in this example is larger than that of the otherfigures, it is simply large to accommodate the thicker plug 10. It wouldalso be possible for the stabilizer 12 to be in multiple pieces. In thecase of multiple plugs 10 in the glass assembly 15, each individual plug10 could have its own stabilizer 12 and/or sealing element 11.

The degree of fluid tightness is largely determined by the number andplacement of sealing elements 11. For example, there could be the samenumber of stabilizers 12 as plugs 10, to avoid twisting, and two sealingelements 11 for each plug 10. For another example, if there are multipleplugs, rather than have one or two sealing elements 11 and onestabilizer 12 per plug, it is possible that there is only a sealingelement 11 in contact with the uppermost plug 10 (as refenced to uphole)and another sealing element 11 in contact with the downhole most plug10. The bearing ring could be in contact with the edges of all of theplugs 10, or only in contact with less than all of the plugs 10. Thiscan be accomplished using a single stabilizer 12 or several stabilizers12.

The sealing area 13 in the case of multiple plugs 10 or multiple layersof material in the plug 10, is determined in the same way as for asingle plug of a single layer (i.e. the regions of the plug 10 that arefluid tight as determined by the sealing element 11 and other possiblecontributors).

FIGS. 3A-3D disclose the operation of a plug tubular 100 in the first,second, and third positions. FIG. 3A disclose the first, startingposition. In FIG. 3A the plug 10 is not moving. FIG. 3B disclose aposition in-between the first position and the second position, wherethe shear ring 50 has sheared and the seat 20 and the plug 10 are movingtoward the breaker object 30. FIG. 3C disclose the second position,where the plug 10 makes contact with the breaker object 30. FIG. 3Ddisclose the third position, where the plug 10 has disintegrated andmovement has ceased.

Thus, a plug assembly 200 has at least three different positions,depending upon the status of the plug's integrity and its position. Inthe first position, the seat 20 is stationary with respect to thetubular body 130 and the plug is intact. After the pressure thresholdrequirements are met, the plug assembly 200 transitions from the firstposition to the second position. In the second position, the seat 20 hasmoved axially until the plug 10 is in contact with the breaker object30. The third position is when the plug 10 is destroyed and fluidconnection is reestablished through the tubular 100. Note that thetubular 100 is in the same position as the plug assembly 200 that ithouses. The plug 10 is arranged in the glass assembly 15. The sealingarea 13 (not shown) would be where each sealing element 11 makes contactwith the housing 140 (not shown) and/or the seat 20 (not shown).

FIG. 4 discloses a plug assembly 200 which comprises a height adjuster40 on one side of the plug 10 and a seat 20 on the other side of theplug 10. The purpose of the height adjuster 40 is to allow for theheight of the housing 140 on one side of the plug 10 to be adjusted. Inthis way, the space can be made larger for installation of the glassassembly 15, the glass assembly 15 inserted into the plug assembly 200,and the space made smaller with the height adjuster 40 to hold the glassassembly 15 in place. This will allow for the plug to be held in placebetter and/or easier installation of the glass assembly 15. This in turnallows for wider tolerances of the glass assembly 15, i.e. the partssaid assembly is made up of can have a wider range of tolerances whenmanufactured, because small differences can be made up for by adjustingthe height adjuster 40.

In the disclosed example, the height adjuster 40 comprises an adjustmentseat 41 and a mechanical adjuster 42. By adjusting the mechanicaladjuster 42 (e.g. a nut or spring), the distance of the height adjuster40 from the plug 10 is changed. In this example, the adjustment of themechanical adjuster 42 moves the adjustment seat 41.

An example of a glass assembly 15 is disclosed comprising a plug 10 (theexample shown is the same as in FIGS. 1A, 1B, 2C, 2D, 3A-3D). Itcomprises a bearing ring 14 between the height adjuster 40 and the plug10 and a second bearing ring 14 between the seat 20 and the plug. Astabilizer 12 is arranged between the outermost edge of the plug 10 andthe housing 140. Sealing element 11 are arranged between each bearingring 14 and the stabilizer 12. As in the previous examples shown, thesealing element 11 is in contact with angled surfaces. In this examplethe seat surface 21 is angled, and the height adjuster 40 in contactwith the sealing element 11 is angled. In the example shown, amechanical adjuster 42 is arranged over the adjustable seat.

In an example, the height adjuster 40 can have threads on the outsidewhich match threads in the housing 140 or tubular body 130. By turningthe height adjuster 40, the gap between the adjustment seat 41 and theplug 10 would be adjusted. The threads do not need to run along theentire body of the height adjuster 40. They can for example run only onthe upper portion (towards uphole) of the height adjustor, while thelower portion (towards the plug) has no threads against the housing butrather a seal against the housing. In this way the height adjuster 40 isa single piece, there is no separate mechanical adjuster 42. This is apreferred example of the height adjuster 40, as only one component isneeded.

Thus, the height adjuster 40 is not limited to the example shown in FIG.4 with the sloped edges and a rounded edge. In another example thereof,if the plug 10 has a square outer edge and does not have bearing ring14, then the height adjuster 40 will normally have a flat surface wherethe adjustment seat 41 makes contact with the plug 10. If there is abearing ring 14, then the adjustment seat 41 will have a contact surfacethat keeps the bearing ring 14 in place on the plug 10. The mechanicaladjuster 42 can be also be a ring with threads along the outside thatmatch treads in the housing 140. As the ring is turned, it pressed downon the adjustment seat 41.

FIGS. 5A-5D disclose different examples of a plug 10 where the plugsurface 60 is made of straight surfaces (lines in the case of the 2Dcross sections). The plug surface 60 comprises a top surface 61, and anedge surface 66. The edge surface comprises a bottom surface, a top edgesurface 63, a middle edge surface 64, and a bottom edge surface 65.

The top edge surface 63 and bottom edge surface 65 are in reference tothe middle edge surface 64. The middle edge surface 64 will be the edgesurface 66 that contains the widest portion of the plug 10. In FIG. 5A,the plug 10 the edge surface 66 only has a middle edge surface 64 andtwo other surfaces (top edge surface 63 and bottom edge surface 65). Theexample plug 10 shown in FIG. 5B is rectangular and thus the edgesurface 66 is the middle edge surface 64 (i.e. no top edge surface 63 orbottom edge surface 65). The example plug 10 shown in FIG. 5C has a plugsurface plug surface 60 with a middle edge surface 64 and a bottom edgesurface 65 (i.e. no top edge surface 63).

However, in examples of the plug 10 in FIG. 5D-5E the middle edgesurface 64 is curved. In the case of FIG. 5D, the middle edge surface 64is arranged between a top edge surface 63 and a bottom edge surface 65.In the example of FIG. 5E, the edge surface 66 does not comprise a topedge surface 63 but does comprise a bottom edge surface 65 and a middleedge surface 64.

In the examples of FIG. 5B, FIG. 5C, and FIG. 5E, there is no top edgesurface 63, in this case the top edge surface 63 is the top surface 61.In the event of a plug 10 with a middle edge surface 64 that has a topedge surface 63 but not a bottom edge surface 65, the bottom surface 62could be considered the bottom edge surface 65.

While the examples of FIGS. 5A, 5B and 5D are symmetrical between topand bottom of the plugs 10, where “top” and “bottom” refers to thefigures, the examples of FIGS. 5C and 5E are not. Please note thatalthough the examples of FIGS. 5C and 5E are drawn in this direction,the direction of such plugs 10 in the well could be upside down fromwhat is shown in said figures. This would depend on the intendedapplication of the glass or plug assembly. If for instance the plug 10of FIG. 5D is to be used in a plug assembly intended to be opened by apressure surge from below the plug assembly, it may be preferable toturn it upside down as compared to the orientation shown in the figure.

FIGS. 6A-8 disclose further examples of the plug assembly 200 andtubular 100. While these figures disclose an example of a sealingbearing ring 16, the elements can be interchanged with the earlierpresented examples. For example, the sealing bearing ring 16 could beexchanged with the bearing ring 14 that was disclosed in the previousexamples. Another example is the positions of the shear ring 50 and thebreaker assembly 32 in FIGS. 6A-9 could be used in the examplesdisclosed previously (and vice versa). The stabilizer 12 is not anessential element these examples.

Note that in the examples there is only a sealing bearing ring 16 on thedownhole side. This is not a requirement. It may be possible for thesealing bearing ring 16 to be on the uphole side only. It is alsopossible for there to be a sealing bearing ring 16 on both the upholeand downhole side. A portion of the sealing could be provided by thesealing bearing ring 16 or it could provide the entire seal of the glassassembly 15.

There may need to be rearrangement of the sealing between differentcomponents in the plug assembly 200 or housing 140 in order to operatein a desired manner. In the examples shown, there is no seal between thebreaker assembly 32 and the housing 140 or between the height adjuster40 and the breaker assembly 32. In this configuration, while it would bepossible to use a sealing bearing ring 16 on the uphole side, it wouldprovide little to no benefit. Because of this, in these configurations,a standard bearing ring 14 is used.

FIG. 6A discloses a side view of a longitudinal cross section of anexample of a plug tubular 100 with a plug assembly 200 in the firstposition.

As in previous examples, the shear ring 50 is comprised of a shear ringlip 51 and shear ring body 52. The shear ring 50 is arranged such thanwhen sufficient force is applied, the shear ring 50 shears at theinterface between the shear ring lip 51 and shear ring body 52.

The plug assembly 200 is arranged in at housing 140 in the tubular body130. In this example it comprises a glass assembly 15, a seat 20, abreaker assembly 32, and a shear ring 50. The glass assembly 15comprises a plug 10, a sealing bearing ring 16 on the bottom side, abearing ring 14 on the uphole side, and a stabilizer 12 around themiddle of the plug 10. The plug 10 is supported by the seat 20. The seat20 is supported by the shear ring lip 51. The breaker assembly 32comprises a breaker object 30 which is arranged in a breaker holder 31.The breaker holder 51 is rests upon the shear ring 50.

The stabilizer 12 is made of a non-elastomeric material. A commonexample of an elastomeric material is rubber. This material is usedprimarily for sealing elements 11. While the properties of rubber arewell suited for sealing, they are entirely unsuitable for stabilizers inthe plug assembly 200. That is because the temperatures and pressuresthat the tubular 100 (and by extension the plug assembly 200) experiencewhen in operation cause the rubber to deform and render them unable toperform their needed function of stabilizing and centralizing the plugin place.

One difference between the examples of FIGS. 6A-9 is that the sealingbearing ring 16 is responsible for (at least partially) maintaining thefluid seal between the uphole and downhole side of the plug 10. Such atype of bearing ring bearing ring 14 will be referred to as a sealingbearing ring 16. In these examples, the sealing bearing ring 16 isentirely responsible for maintaining this seal. As is the case with thestabilizer 12, the sealing bearing ring 16 (and the bearing ring 14disclosed previously) should be made of a non-elastomeric material.

An elastomeric material is simply not suitable for a sealing bearingring 16. The temperatures and pressures can cause it to deform. Thereare several possible negative consequences that can occur if using anelastomeric bearing ring 11. Most commonly is that the elastomericmaterial will be forced out from its place between the housing 140 andthe plug 10. Other examples include the possibility that deformationwill break the seal around the plug 10 allowing the fluid to flow, causepremature rupture of the plug 10, or cause the plug 10 to twist duringoperation.

Examples of suitable non-elastomeric materials for the stabilizer 12 orthe sealing bearing ring 16 include thermo plastics, PEEK, soft metals,and other materials that can hold their shape well enough underoperating conditions and not be squeezed out of form such that there isnot enough support of the plug 10 or metal to metal contact between theplug 10 and another element of the plug assembly 200 or tubular 100. Itis possible to coat a suitable material with rubber in order to improvethe sealing properties of the sealing bearing ring 16, however therubber is no able to accomplish the task alone.

The breaker holder 31 is shown as resting upon the shear ring 50.However, this is not necessary. As seen in previous examples, thebreaker assembly 32 is arranged to keep the breaker object 30 inposition such that the plug 10 can make impact with the breaker object30. This is usually because the breaker object 30 is stationary withrespect to the housing 140. One way to accomplish this is to attach thebreaker object 30 or breaker assembly 32 to the housing directly.

FIG. 6B discloses a closeup of the plug tubular 100 and plug assembly200 example as disclosed in FIG. 6A in the first position. The glassassembly 15 comprises a plug 10 with a sealing bearing ring 16 ondownhole side of the plug, a bearing ring 14 on the uphole side of theplug, and a stabilizer 12 around its middle surface.

FIGS. 6C-6F discloses the plug tubular 100 example disclosed in FIG. 6Aas the plug assembly 200 moves from the first position to the secondposition. When the pressure on the plug 10 is high enough, the seat 20,which is supported by the shear ring lip 51 causes the shear ring lip 51to separate from the shear ring body 52. The seat 20 is now unsupportedand will move and make contact with the breaker object 30. A stabilizer12 helps to stabilize and center the plug 10. A sealing bearing ring 16one side and a bearing ring 14 on the other. The sealing bearing ring 16provides the sealing of the plug assembly 200.

FIG. 6C discloses the state of the plug assembly 200 after the shearring 50 has sheared, but before the plug 10 has made contact with thebreaker object 30. FIG. 6D shows the second position where the plug 10made contact with the breaker object 30. FIG. 6E shows the breakerobject 30 continuing through the plug 10 after the initial contact shownin FIG. 6D. Finally, FIG. 6F shows the plug assembly 200 in the thirdposition where the plug 10 has been destroyed and flow through thetubular 100 is restored.

The bearing ring 14 above on uphole side of the plug 10, does not remainin contact with the plug 10 when the plug assembly 200 moves from thefirst to the third position. This is due to the bearing ring 14 restingon a shoulder in the breaker assembly 32. Note that it is possible forboth the bearing ring 14 and the sealing bearing ring 16 to move withthe plug 10. It is an advantage if the sealing bearing ring 16 moveswith the plug as this maintains the fluid seal around the plug duringthe transition from the first to the second position.

FIG. 7 discloses an example of a breaker assembly 32 in a plug assembly200. In this example, the shear ring body 52 is part of the breakerassembly 32, rather than a separate element as in many of the previouspresented examples. One advantage of this may be that it can result inless installation time for a single element than installing twoelements.

FIGS. 8A and 8B disclose an example of a height adjuster 40 of the plugassembly 200 in the first and third positions. This is a further exampleof the disclose of FIG. 4 (with accompanying discussion). As discussedabove, only the downhole sealing bearing ring 16 moves with the plug 10when moving from the first position. The bearing ring 14 remains inplace. The shoulder in the housing 140 that the bearing ring 14 restsagainst, helps to prevent the height adjuster 40, the adjustment seat41, mechanical adjuster 42 from putting too much pressure on the plug10. This shoulder is not necessary as it is possible for the heightadjuster 40 itself to provide the needed pressure.

In this example, the mechanical adjuster 42 of the height adjuster 40 isa coil spring. In addition to some of the examples of mechanicaladjusters 42 that were disclosed in the discussion of FIG. 4 , wavesprings, tension wires, disc springs, or other suitable tension deviceswould work as the mechanical adjuster.

While the height adjuster 40 disclosed in the previous examples have theheight adjuster 40 applying force to the plug 10 and in the direction ofthe seat, this is not a requirement. In some cases, the height adjuster40 could be a part of the seat 20 and would direct force through theplug 10 in the direction of the housing 140.

It may also be possible to apply a radial force from the height adjuster40 rather than an axial force. A radial force could be used to hold theplug 10 in place by pushing it from the sides. One possibility of thiswould be to have height adjuster 40 arranged between the bearing rings.

The size of the height adjuster 40 is adjustable and can be changed. Thespecific type of height adjuster 40 will determine the exact way bywhich the size is changed. In figures that were disclosed, the sizeadjustment is in the axial axis of the plug assembly 200 and tubular100. However as discussed above, it may be desirable to have a change insize possible in the radial axis.

One example of how the size of the height adjuster 40 can be changed iswith height adjusters 40 that comprise springs. The size will change asthe spring is compressed or expanded. Another example of how the size ofthe height adjuster 40 can be changed is with height adjuster 40 that donot have a restorative property to them. The height adjuster 40 willremain at a specific size until they are adjusted to another size. Inboth cases, the size of the height adjuster 40 is adjustable.

In the disclosed examples of a height adjuster 40 in this application,there are two broad types of height adjusters 40 that have beenpresented. The first kind are those that do not have any restorativeproperty to them (non-restorative). For these, the size of the heightadjuster 40 does not change size until it is adjusted. This kind ofnon-restorative height adjuster 40 devices have a first position wherethere is no pressure applied to the plug 10, and a second position wherethe height adjuster 40 is in contact with the plug 10 and appliespressure. The mechanical adjuster 42 will adjust the pressure applied bythe adjustment seat 41 until the desired amount of pressure is applied.

Another disclosed type was a height adjuster 40 with a tension device orspring (usually as the mechanical adjuster 42). These are restorativetypes of height adjusters 40. In these, the initial position is when theglass assembly 15 makes contact with the height adjuster 40. The springwill compress, and the pressure applied by the height adjuster 40 on theglass assembly 15 will increase. In the second position, the glassassembly 15 is in place and the spring will have expanded, and thepressure on the glass assembly 15 due to the height adjuster 40 willdecrease. Note that if the spring was biased in the opposite manner,then the pressure would first decrease and then increase in the secondposition.

In both restorative and non-restorative examples, the height adjuster's40 height is determined by the mechanical adjuster 42. For thenon-restorative, it is the distance of the mechanical adjuster 42 thatmoves to push the adjustment seat 41 against the glass assembly 15. Fora restorative height adjuster 40, it is the size of the spring as itcompresses and expands.

In both of these two examples of height adjuster 40 categories, thepressure applied by the height adjuster 40 on the glass assembly 15between the first and second position are not the same. It may bepossible to have a height adjuster in which the first and secondposition have the same pressures depending upon the exact mechanism bywhich the height adjuster 40 operates.

Another example of a height adjuster 40 is one with a fluid for amechanical adjuster 42. For example, the adjustment seat 41 could be influid contact with a fluid. Increasing pressure of the fluid to theadjustment seat 41 would push the adjustment seat 41 to increasepressure. Reducing the amount of fluid pressure would decrease thepressure that adjustment seat 41 applies to the glass assembly 15.

In operation, normally the height adjuster 40 will be adjusted such thatit applies enough force on the plug 10 so that the plug 10 remains inplace during operation of the plug assembly 200 when being operated in aclosed position. In some examples disclosed, the fixed position withrespect to the housing will be temporary as the plug 10 does eventuallymove in the axial direction to be broken. In other examples, such aswith explosives, it is possible for the plug 10 to remain in itsoriginal place when it is broken.

Another way in which a height adjuster 40 could operate would be to movethe adjustment seat 41 into contact with the glass assembly 15 and theninsert a physical stop such that the height adjuster 40 could not moveenough for the glass assembly 15 to become too loose for the plugassembly 200 to perform its intended function.

As discussed previously, only the downhole sealing bearing ring 16 moveswith the plug 10 when moving from the first position. The uphole bearingring 14 remains in place. The shoulder in the housing 140 that theuphole bearing ring 14 rests against, helps to prevent the heightadjuster 40, the adjustment seat 41, and/or mechanical adjuster 42 fromputting too much pressure on the plug 10.

One reason for this is that it allows the height adjuster 40 to provideenough force to keep the plug 10 in place during operation, but not somuch that it causes the plug 10 to break prematurely or otherwise causethe plug assembly 200 to not operate as intended.

This shoulder is not necessary as it is possible for the height adjuster40 itself to provide the needed pressure without risking of putting toomuch pressure on the plug 10. Also note that the feature of the upholebearing ring 14 remaining stationary is not essential.

Also note that the stabilizer 12 is arranged in a groove within thebreaker assembly 32 so that it does not move. However, this is notrequired. It can be an advantage in some applications if the stabilizer12 moves with the plug 10.

FIG. 9 discloses an 3D exploded view of an example of a plug assembly200. The plug assembly 200 comprises a sealing bearing ring 16 on thedownhole side of the plug 10 and a bearing ring 14 on the uphole side ofthe plug 10. Around the bottom edge surface 65 is arranged a stabilizer12. In the example shown the stabilizer 12 has a slit in it; renderingit non-fluid tight. In the example disclosed the sealing bearing ring 16has a hole through it on the edge. In this way, it is possible for thesealing bearing ring 16 to seal between the plug 10 and the housing 140(not shown) without sealing on the edge portion which is often against avertical surface. Lack of sealing on the parallel sides of the housing140 can make it easier for the housing 140 to move from the firstposition to the second position.

Note that even though the examples of FIG. 8A and FIG. 8B does not haveany sealing elements 11 (not shown) this configuration is possible. Thiswould be similar to the examples present previously where there is asealing element between the stabilizer 12 and the bearing ring 14.

The examples have been disclosed the stabilizer 12 as being arranged ina recess in the breaker assembly 32. The breaker object 30 can bemounted directly in the wall. It would be possible for the recess to bein the housing 140 or tubular body 130. The examples show that thestabilizer 12 remains in place as the plug assembly 200 duringtransition from the first position to the second position, this is notnecessary. It could be allowed to move with the plug 10. This may beuseful to help stabilize the plug 10 when changing position to furtheraid in keeping the plug 10 aligned correctly.

The meaning of the example of a stabilizer 12 that is not fluid tight isthat the stabilizer 12 has no role in providing a fluid seal in theglass assembly 15 or the glass assembly when in the plug assembly (200).In other words, the stabilizer 12 alone would not provide enoughsealing, or any at all, to prevent fluid from going around the plug 10.This role is filled by one or more sealing elements 11 and/or one ormore sealing bearing rings 16.

Please note that “step of” is not to be interpreted as “step for”. By“comprised of”, “comprising”, “comprises” etc. we are referring to anopen set and by “consisting of” we are referring to a closed set.

Modifications to the embodiments previously described are possiblewithout departing from the scope of the invention as defined by theaccompanying claims. Numerals included within parentheses in theaccompanying claims are intended to assist understanding of the claimsand should not be construed in any way to limit the subject matterclaimed. Reference to the singular is also to be construed as relatingto the plural unless expressly stated otherwise. Any reference numbersin the claims are provided as a courtesy and are not to be interpretedas limiting the claim in any way.

It is hereby claimed:
 1. A glass assembly (15) comprising: a plug (10)with a top surface (61) and a bottom surface (62); and a sealing bearingring at least partially made of a non-elastomeric material; wherein: thesealing bearing ring (16) arranged on the top surface (61) or the bottomsurface (62) of the plug (10).
 2. The glass assembly (15) according toclaim 1, further comprising a non-sealing bearing ring (14), wherein thebearing ring is (14) on the opposite surface (61,62) of the plug (10)from the sealing bearing ring (16).
 3. The glass assembly (15) accordingto claim 1, further comprising a stabilizer (12) and wherein: the plug(10) further comprises a middle edge surface (64) which contains thewidest portion of the plug (10); and the stabilizer (12) is arrangedaround at least a portion of the middle edge surface (64).
 4. The glassassembly (15) according to claim 2, further comprising a stabilizer (12)and wherein: the plug (10) further comprises a middle edge surface (64)which contains the widest portion of the plug (10); and the stabilizer(12) is around the middle edge surface (64).
 5. The glass assembly (15)according to claim 1, wherein the sealing bearing ring (16) is entirelymade of a non-elastomeric material.
 6. The glass assembly (15) accordingto claim 3, wherein the stabilizer is made of a non-elastomericmaterial.
 7. The glass assembly (15) according to claim 3, wherein thestabilizer (12) is not fluid tight.
 8. The glass assembly (15) accordingto claim 3, wherein the sealing bearing ring (16) comprises athermoplastic material.
 9. A plug assembly (200) comprising: a glassassembly (15), arranged in a housing (140); the glass assembly (15)comprising a plug with a top surface (61) and a bottom surface (62); asealing bearing ring (16) at least partially made of a non-elastomericmaterial the sealing bearing ring (16) arranged on the top surface (61)or the bottom surface (62) of the plug (10); a seat (20) arranged tosupport the plug (10); and a breaker object (30) configured to break theplug (10); wherein the sealing bearing ring (16) provides a seal betweenthe glass assembly (15) and the housing (140).
 10. The plug assembly(200) according to claim 9 wherein the glass assembly (15) furthercomprises a non-sealing bearing ring (14), wherein the bearing ring is(14) on the opposite surface (61,62) of the plug (10) from the sealingbearing ring (16).
 11. The plug assembly (200) according to claim 9,wherein the sealing bearing ring (16) is made entirely of anon-elastomeric material.
 12. The plug assembly (200) according to claim9, wherein the glass assembly (15) has an uphole and downhole side,wherein no bearing ring (14) or sealing bearing ring (16) on the upholeside of the in the glass assembly (16), and the sealing bearing ring(16) is arranged on the downhole side of the glass assembly (15). 13.The plug assembly (200) according to claim 9, wherein the glass assembly(15) further comprises a stabilizer (12) and wherein: the plug (10)further comprises a middle edge surface (64) which contains the widestportion of the plug (10); and the stabilizer (12) is arranged around atleast a portion of the middle edge surface (64).
 14. The plug assembly(200) according to claim 10, wherein the glass assembly (15) furthercomprises a stabilizer (12) and wherein: the plug (10) further comprisesa middle edge surface (64) which contains the widest portion of the plug(10); and the stabilizer (12) is arranged around at least a portion ofthe middle edge surface (64).
 15. The plug assembly (200) according toclaim 13, wherein the stabilizer (12) is not fluid tight.
 16. The plugassembly (200) according to claim 14, wherein the stabilizer (12) is notfluid tight.
 17. The plug assembly (200) according to claim 9, whereinthe seat (20) is arranged to move in an axial direction toward thebreaker object (30) when a threshold absolute pressure or thresholddifferential pressure is reached.
 18. The plug assembly (200) accordingto claim 9, further comprising a shear ring (50), the shear ring (50)comprising a shear ring lip (51); and wherein the seat (20) is supportedby the shear ring lip (51), the shear ring lip (51) arranged to shearand allow the seat (20) to move when a threshold absolute pressure, orthreshold differential pressure, is reached.
 19. The plug assembly (200)according to claim 9, further comprising a breaker holder (31), whereinthe breaker holder (31) is configured to hold the breaker object (30)fixed in place relative to the plug (10).
 20. The plug assembly (200)according to claim 9, further comprising a sealing area (13), whereinthe sealing area (13) is a region of the housing (140) and seat (20) incontact with the sealing bearing ring (16) and wherein, the sealing area(13) is non-parallel with the axial axis of the plug assembly (200). 21.The plug assembly (200) according to claim 9, wherein the sealingbearing ring (16) has a through hole that prevents the sealing bearingring (16) from sealing at a parallel portion of the housing (14). 22.The plug assembly (200) according to claim 13, wherein the glassassembly (15) has an uphole side and downhole side, wherein there is nobearing ring (14) or sealing bearing ring (16) on the uphole side andthe sealing bearing ring (16) is arranged on the downhole side of theglass assembly (15).